The Chaos That Sepsis-3 Has Wrought
To the Academy: I understand why the changes were made, and they have caused so much upheaval
In 2016, a new definition for sepsis was published by a task force convened by the European Society of Intensive Care Medicine and the U.S.-based Society of Critical Care Medicine. The task force’s job, as noted in the article, was to “differentiate sepsis from uncomplicated infection and to update definitions of sepsis and septic shock to be consistent with improved understanding of the pathobiology.”
Prior to this publication, sepsis was defined the presence of a known or suspected infection, with two or more SIRS criteria. SIRS stands for the “Systemic Inflammatory Response Syndrome,” and it is typically defined as two or more of the following:
Temperature greater than 38°C or less than 36°C
Heart rate greater than 90/min
Respiratory rate greater than 20/min or Paco2 less than 32 mm Hg (4.3 kPa)
White blood cell count greater than 12 000/mm3 or less than 4000/mm3 or >10% immature bands
Reference: Bone RC, Balk RA, Cerra FB, et al. American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference: definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. Crit Care Med. 1992;20(6):864–874.
This definition had been in use for decades, and the task force noted that the “current use of 2 or more SIRS criteria to identify sepsis was unanimously considered by the task force to be unhelpful. Changes in white blood cell count, temperature, and heart rate reflect inflammation, the host response to “danger” in the form of infection or other insults…SIRS criteria are present in many hospitalized patients, including those who never develop infection and never incur adverse outcomes (poor discriminant validity).”
They were right about that. SIRS is very nonspecific. Almost anything can cause one to have at least two SIRS criteria. For example, if I watch a particularly frightening movie, I bet I can have two SIRS criteria: (1) a heart rate more than 90, and (2) a respiratory rate more than 20.
What sepsis is, however, is life-threatening organ failure as a result of infection. SIRS is just a marker of inflammation, not organ failure. For example, if someone gets the flu and has a fever and fast heart rate, they technically have two SIRS criteria and an infection. That does NOT mean that they are septic.
That was the problem with the previous definition (called Sepsis-2), and that is why a change was sought. Furthermore, the task force noted: “the public needs an understandable definition of sepsis, whereas health care practitioners require improved clinical prompts and diagnostic approaches to facilitate earlier identification and an accurate quantification of the burden of sepsis.”
And so, after doing extensive research on 1.3 million patients, the task force came up with this new, updated definition: “Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection.” In lay terms, sepsis is a “life-threatening condition that arises when the body’s response to an infection injures its own tissues and organs.”
How does one define “life-threatening organ dysfunction”? By using the SOFA score: “Organ dysfunction can be identified as an acute change in total SOFA score 2 points consequent to the infection.” What’s SOFA? It is the Sequential (Sepsis-related) Organ Failure Assessment score, and it is derived from the following:
The worse the oxygen level, platelet count, bilirubin, blood pressure, mental status, and kidney function, the higher the SOFA score is. A SOFA score of 2 or greater equated a risk of 10% mortality in a general hospital population with suspected infection.
This was a pretty major change, and it was not without controversy, as the task force acknowledged:
There are inherent challenges in defining sepsis and septic shock. First and foremost, sepsis is a broad term applied to an incompletely understood process. There are, as yet, no simple and unambiguous clinical criteria or biological, imaging, or laboratory features that uniquely identify a septic patient. The task force recognized the impossibility of trying to achieve total consensus on all points. Pragmatic compromises were necessary, so emphasis was placed on generalizability and the use of readily measurable identifiers that could best capture the current conceptualization of underlying mechanisms.
The task force also said:
The debate and discussion that this work will inevitably generate are encouraged. Aspects of the new definitions do indeed rely on expert opinion; further understanding of the biology of sepsis, the availability of new diagnostic approaches, and enhanced collection of data will fuel their continued reevaluation and revision.
I don’t think the task force realized, however, the chaos that this new definition has wrought since its publication.
The new definition of sepsis has created chaos and confusion. The answer is not scrapping the definition, but rather getting more sophisticated as clinicians.
I was speaking to a Chief Medical Officer of a community hospital, and he said to me, “For years we trained providers to lower the bar on who met criteria for sepsis to meet CMS’ quality expectations. Now that same practice is putting us at odds with commercial payers. The dual definitions of sepsis have become very challenging.” He also added that his hospital has hundreds of thousands, if not millions, of dollars on the line because auditors are now going back and denying a diagnosis of sepsis based on the new definition.
Indeed, I have reviewed dozens of medical records who have had sepsis denials because the doctor was using Sepsis-2, and the auditor was using Sepsis-3. Many times, I had to agree with the auditor.
For example, say a 45-year-old man presents to the hospital with a urinary tract infection, a fever of 102, and a heart rate of 120. Under Sepsis-2, he meets criteria for sepsis. Under Sepsis-3, however, he does not. And if an auditor looks at that chart and denies a diagnosis of sepsis, they would be technically correct.
Confusion and chaos abounds.
Now, I am not advocating that Sepsis-3 gets scrapped. Sepsis-2 was way too vague, and it assigned a diagnosis of “sepsis” to patients who had a simple, uncomplicated infection. The task force was right to clarify the definition of sepsis based on the most recent evidence and understanding of the pathophysiology, especially when conducting research on sepsis.
At the same time, auditors are having a field day with sepsis denials, and it is placing a heavy strain on hospital finances and resources in fighting these denials through secondary reviews and appeals (of which I have done dozens). The solution? Clinicians need to get much more sophisticated.
To be continued…
The opinions expressed in this post are my own, and they do not reflect those of my employer or those institutions with which I am affiliated.